We don't know if they just stopped or they discussed it with Ryanair prior to the announcement. There is a lot more to this I expect, will be an interesting case.
Hertz have had a huge push on Ryanair business in 2015 apparently in Uk as told to me at Hertz office I normally use. Regular calls with managers around the business highlight who is top and bottom. Announcement made that as Hertz losing money apparently then that was why they walked away.